arch/arm/mach-ep93xx/gpio.c

   1 /*
   2  * linux/arch/arm/mach-ep93xx/gpio.c
   3  *
   4  * Generic EP93xx GPIO handling
   5  *
   6  * Copyright (c) 2008 Ryan Mallon <ryan@bluewatersys.com>
   7  *
   8  * Based on code originally from:
   9  *  linux/arch/arm/mach-ep93xx/core.c
  10  *
  11  *  This program is free software; you can redistribute it and/or modify
  12  *  it under the terms of the GNU General Public License version 2 as
  13  *  published by the Free Software Foundation.
  14  */
  15
  16 #include <linux/init.h>
  17 #include <linux/module.h>
  18 #include <linux/seq_file.h>
  19 #include <linux/io.h>
  20
  21 #include <mach/ep93xx-regs.h>
  22 #include <asm/gpio.h>
  23
  24 struct ep93xx_gpio_chip {
  25         struct gpio_chip        chip;
  26
  27         unsigned int            data_reg;
  28         unsigned int            data_dir_reg;
  29 };
  30
  31 #define to_ep93xx_gpio_chip(c) container_of(c, struct ep93xx_gpio_chip, chip)
  32
  33 /* From core.c */
  34 extern void ep93xx_gpio_int_mask(unsigned line);
  35 extern void ep93xx_gpio_update_int_params(unsigned port);
  36
  37 static int ep93xx_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
  38 {
  39         struct ep93xx_gpio_chip *ep93xx_chip = to_ep93xx_gpio_chip(chip);
  40         unsigned long flags;
  41         u8 v;
  42
  43         local_irq_save(flags);
  44         v = __raw_readb(ep93xx_chip->data_dir_reg);
  45         v &= ~(1 << offset);
  46         __raw_writeb(v, ep93xx_chip->data_dir_reg);
  47         local_irq_restore(flags);
  48
  49         return 0;
  50 }
  51
  52 static int ep93xx_gpio_direction_output(struct gpio_chip *chip,
  53                                         unsigned offset, int val)
  54 {
  55         struct ep93xx_gpio_chip *ep93xx_chip = to_ep93xx_gpio_chip(chip);
  56         unsigned long flags;
  57         int line;
  58         u8 v;
  59
  60         local_irq_save(flags);
  61
  62         /* Set the value */
  63         v = __raw_readb(ep93xx_chip->data_reg);
  64         if (val)
  65                 v |= (1 << offset);
  66         else
  67                 v &= ~(1 << offset);
  68         __raw_writeb(v, ep93xx_chip->data_reg);
  69
  70         /* Drive as an output */
  71         line = chip->base + offset;
  72         if (line <= EP93XX_GPIO_LINE_MAX_IRQ) {
  73                 /* Ports A/B/F */
  74                 ep93xx_gpio_int_mask(line);
  75                 ep93xx_gpio_update_int_params(line >> 3);
  76         }
  77
  78         v = __raw_readb(ep93xx_chip->data_dir_reg);
  79         v |= (1 << offset);
  80         __raw_writeb(v, ep93xx_chip->data_dir_reg);
  81
  82         local_irq_restore(flags);
  83
  84         return 0;
  85 }
  86
  87 static int ep93xx_gpio_get(struct gpio_chip *chip, unsigned offset)
  88 {
  89         struct ep93xx_gpio_chip *ep93xx_chip = to_ep93xx_gpio_chip(chip);
  90
  91         return !!(__raw_readb(ep93xx_chip->data_reg) & (1 << offset));
  92 }
  93
  94 static void ep93xx_gpio_set(struct gpio_chip *chip, unsigned offset, int val)
  95 {
  96         struct ep93xx_gpio_chip *ep93xx_chip = to_ep93xx_gpio_chip(chip);
  97         unsigned long flags;
  98         u8 v;
  99
 100         local_irq_save(flags);
 101         v = __raw_readb(ep93xx_chip->data_reg);
 102         if (val)
 103                 v |= (1 << offset);
 104         else
 105                 v &= ~(1 << offset);
 106         __raw_writeb(v, ep93xx_chip->data_reg);
 107         local_irq_restore(flags);
 108 }
 109
 110 static void ep93xx_gpio_dbg_show(struct seq_file *s, struct gpio_chip *chip)
 111 {
 112         struct ep93xx_gpio_chip *ep93xx_chip = to_ep93xx_gpio_chip(chip);
 113         u8 data_reg, data_dir_reg;
 114         int i;
 115
 116         data_reg = __raw_readb(ep93xx_chip->data_reg);
 117         data_dir_reg = __raw_readb(ep93xx_chip->data_dir_reg);
 118
 119         for (i = 0; i < chip->ngpio; i++)
 120                 seq_printf(s, "GPIO %s%d: %s %s\n", chip->label, i,
 121                            (data_reg & (1 << i)) ? "set" : "clear",
 122                            (data_dir_reg & (1 << i)) ? "out" : "in");
 123 }
 124
 125 #define EP93XX_GPIO_BANK(name, dr, ddr, base_gpio)                      \
 126         {                                                               \
 127                 .chip = {                                               \
 128                         .label            = name,                       \
 129                         .direction_input  = ep93xx_gpio_direction_input, \
 130                         .direction_output = ep93xx_gpio_direction_output, \
 131                         .get              = ep93xx_gpio_get,            \
 132                         .set              = ep93xx_gpio_set,            \
 133                         .dbg_show         = ep93xx_gpio_dbg_show,       \
 134                         .base             = base_gpio,                  \
 135                         .ngpio            = 8,                          \
 136                 },                                                      \
 137                 .data_reg       = EP93XX_GPIO_REG(dr),                  \
 138                 .data_dir_reg   = EP93XX_GPIO_REG(ddr),                 \
 139         }
 140
 141 static struct ep93xx_gpio_chip ep93xx_gpio_banks[] = {
 142         EP93XX_GPIO_BANK("A", 0x00, 0x10, 0),
 143         EP93XX_GPIO_BANK("B", 0x04, 0x14, 8),
 144         EP93XX_GPIO_BANK("C", 0x08, 0x18, 40),
 145         EP93XX_GPIO_BANK("D", 0x0c, 0x1c, 24),
 146         EP93XX_GPIO_BANK("E", 0x20, 0x24, 32),
 147         EP93XX_GPIO_BANK("F", 0x30, 0x34, 16),
 148         EP93XX_GPIO_BANK("G", 0x38, 0x3c, 48),
 149         EP93XX_GPIO_BANK("H", 0x40, 0x44, 56),
 150 };
 151
 152 void __init ep93xx_gpio_init(void)
 153 {
 154         int i;
 155
 156         for (i = 0; i < ARRAY_SIZE(ep93xx_gpio_banks); i++)
 157                 gpiochip_add(&ep93xx_gpio_banks[i].chip);
 158 }